Page 44 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

E BC

FIGURE 3-7 Common silicon transistor.
The figure shows the most common lead configuration for the most common
transistors, such as 2N4124, 2N4126, 2N3904 (as shown in the figure), 2N3906,
2NS087, and 2N5089. If other transistors are substituted, the lead configuration

diagram can be downloaded from the Web (e.g., go to Google, and type in
"2iNxxxx, BCxxx, etc. data sheet"). As shown in Figure 3-7, the base and collector
, leads are next to each other, causing increased internal capacitance between the
base and collector leads.
For high-frequency transistors, which will be used in some designs in this book, the

lead terminal configuration is changed to B, E, C (base, emitter, collector), as
shown in Figure 3-8.